The original design took one car-sized lane on each side of the current median. The new design squeezes the lanes into the existing median in most areas. Where there are wide pedestrian refuges at the ends of blocks, the lanes cut into those refuges, extending over the stone pavers but around the existing poles.

The lanes did confuse some drivers, who occasionally thought they were turn lanes or regular driving lanes. Since the lanes were never officially opened, we can't really know if those problems would have worked themselves out or DDOT would have found simple ways to fix those problems without fundamentally rethinking the lanes.
Some changes probably were necessary. However, it would have been better to open the lanes and then have a more public conversation about any issues and how to solve them. Instead, whether for political or other reasons, DDOT skipped that step.

The narrower lanes appear to be much less safe for cyclists. In some places, such as between 13th and 14th Streets, there is no buffer at all between traffic and the lanes.

Bike lanes are a great idea in light of promoting exercise and reducing pollution, but when DDOT essentially cut the driving lanes and made these weird bus lanes to accommodate bikers, it created confusion with drivers and actually more of a danger for cyclists. After all, as this city was built up, it did not have a european style layout. The only thing Roman are the buildings downtown. Face it, the drivers in this city are impatient and some are careless despite what you do with speed limits and cameras, and manouvering around cyclists, who certainly aren't peddling anywhere near speed limit, can be a pain in the butt for many, motivating them to be more wreckless.

Personally, I think that it would've been better to reduce the width of the sidewalks to make the biking lanes, like they do in Germany. It keeps pedestrians safe and gives cars and bikers more room. Despite the foot traffic in DC, pedestrians really don't need these expansively wide sidewalks to get around in a timely fashion. The biggest hinderance to pedestrians is the timing and lack of countdown features on the traffic lights.